Fact-checked by Grok 2 weeks ago

Elbow

The elbow is a complex synovial hinge joint in the human upper limb that connects the humerus of the upper arm to the radius and ulna bones of the forearm, enabling essential movements such as flexion, extension, pronation, and supination.^[1] Formed by three distinct articulations—the humeroulnar, humeroradial, and proximal radioulnar joints—it combines hinge-like motion for bending and straightening the arm with pivot functionality for forearm rotation, supported by a joint capsule, hyaline cartilage for smooth gliding, and surrounding ligaments and muscles.^[1] This structure provides stability and versatility for daily activities, weight-bearing, and fine motor tasks, while its relatively shallow bony architecture relies heavily on soft tissues to prevent instability or dislocation.^[1] Anatomically, the elbow's bony framework includes the distal humerus with its trochlea and capitulum, the proximal ulna featuring the olecranon process, and the proximal radius with its head, all enclosed within a fibrous capsule that allows for a range of motion of approximately 150° of flexion and 0° of extension (full extension).^[1]^[2]^[3] Key ligaments include the medial (ulnar) collateral ligament, which resists valgus stress on the inner side; the lateral (radial) collateral ligament complex, preventing varus stress on the outer side; and the annular ligament, which encircles the radial head to maintain its alignment during rotation.^[1] Muscles acting across the joint encompass flexors like the biceps brachii and brachialis, extensors such as the triceps brachii, and rotators including the supinator and pronator teres, all innervated by branches of the musculocutaneous, radial, and median nerves, with blood supply primarily from the brachial artery and its branches including the profunda brachii.^[1]^[4] Functionally, the elbow serves as a critical pivot for force transmission from the shoulder to the hand, contributing to propulsion in activities like throwing or pushing, and its biomechanics are optimized for both stability during load-bearing and mobility for reaching.^[1] Common issues arise from overuse, trauma, or degeneration, leading to conditions such as epicondylitis (tennis or golfer's elbow), bursitis, or fractures, which highlight the joint's vulnerability despite its robust design.^[1]

Anatomy

Bones and Joints

The elbow joint is formed by the articulation of three primary bones: the distal humerus from the upper arm, and the proximal portions of the radius and ulna from the forearm. This skeletal framework enables the combined movements of flexion-extension and pronation-supination, classifying the elbow as a trochoginglymus joint.^[5] The distal end of the humerus presents two key articular surfaces: the spool-shaped trochlea medially, which is grooved to engage with the ulna, and the rounded capitulum laterally, which articulates with the radius.^[6] Above these, the humerus features medial and lateral epicondyles, with the trochlea's medial position contributing to the joint's valgus alignment. The proximal ulna includes the olecranon process posteriorly, a hook-like projection that fits into the olecranon fossa of the humerus during extension, and the trochlear notch anteriorly, a large concavity formed by the olecranon and the anterior coronoid process, which wraps around the humeral trochlea for stability.^[5] The coronoid process, a triangular eminence, further deepens this notch and provides attachment points for joint capsule reinforcements.^[6] The proximal radius consists of the discoid radial head, which has a fovea articulating with the humerus and a circumferential rim engaging the ulna, connected to the shaft by the narrower radial neck. This structure allows the radius to pivot around the ulna during forearm rotation.^[5] Structurally, the elbow comprises three synovial articulations: the ulnohumeral joint, functioning as a hinge (ginglymus) for flexion and extension between the humeral trochlea and ulnar trochlear notch; the humeroradial joint, resembling a ball-and-socket due to the capitulum-radius head contact, which supports both hinge and pivot motions; and the proximal radioulnar joint, a pivot (trochoid) joint between the radial head and the ulnar radial notch, facilitating pronation and supination.^[6] These surfaces are covered in hyaline cartilage to reduce friction. In the anatomical position of full extension, the angle between the humerus and forearm measures 180°^[7], allowing efficient arm positioning for daily activities. The hinge component permits a flexion range up to about 150° from this extended baseline.^[6]

Muscles and Tendons

The primary muscles responsible for flexion at the elbow joint include the biceps brachii, brachialis, and brachioradialis. The biceps brachii consists of two heads: the long head originates from the supraglenoid tubercle of the scapula, while the short head arises from the coracoid process of the scapula; both heads converge to insert on the radial tuberosity and via the bicipital aponeurosis to the fascia of the forearm flexors.^[8] The brachialis originates from the distal half of the anterior humerus and inserts on the coronoid process and tuberosity of the ulna.^[9] The brachioradialis originates from the lateral supracondylar ridge of the humerus and inserts on the lateral aspect of the distal radius near the styloid process.^[10] Extension at the elbow is primarily driven by the triceps brachii and the smaller anconeus muscle. The triceps brachii has three heads: the long head originates from the infraglenoid tubercle of the scapula, the lateral head from the posterior surface of the humerus above the radial groove, and the medial head from the posterior humerus below the radial groove; all three heads insert via a common tendon on the olecranon process of the ulna. The anconeus originates from the lateral epicondyle of the humerus and inserts on the olecranon and proximal posterior ulna, assisting in extension and stabilizing the joint during movement.^[11] Pronation of the forearm involves the pronator teres and pronator quadratus. The pronator teres has two heads: the humeral head originates from the medial epicondyle of the humerus via the common flexor tendon, and the ulnar head from the coronoid process of the ulna; it inserts on the mid-lateral surface of the radius.^[12] The pronator quadratus, located distally, originates from the anterior surface of the distal ulna and inserts on the anterior surface of the distal radius.^[13] Supination of the forearm is achieved mainly by the supinator muscle, with a significant contribution from the biceps brachii. The supinator originates from the lateral epicondyle of the humerus, the supinator crest of the ulna, and the radial collateral ligament, inserting along the lateral, anterior, and posterior surfaces of the proximal radius.^[14] The biceps brachii enhances supination, particularly when the elbow is flexed, due to its insertion on the radius.^[8] The tendons associated with these muscles provide critical connections between contractile elements and bone. The biceps tendon, specifically its distal portion, measures approximately 6 cm in length from the muscle belly to the radial tuberosity.^[15] Forearm flexors such as the pronator teres, flexor carpi radialis, and palmaris longus share a common flexor origin at the medial epicondyle of the humerus.^[13] Similarly, the extensor muscles, including the extensor carpi radialis brevis and extensor digitorum, arise from a common extensor origin at the lateral epicondyle of the humerus.^[16]

Ligaments and Capsule

The elbow joint is enclosed by a fibrous capsule that provides structural integrity while permitting hinge-like movements. This capsule originates from the humerus at the margins of the articular surfaces, specifically from the lateral and medial supracondylar ridges, and extends distally to attach to the ulna and radius. Anteriorly, the capsule is relatively thin and loose to accommodate flexion, attaching to the coronoid process of the ulna and the annular ligament around the radial neck; posteriorly, it is reinforced and attaches to the olecranon process and the posterior radial neck.^[4] The capsule's synovial membrane lines its inner surface, secreting synovial fluid for lubrication and nourishment of the articular cartilage, and forms expansions into adjacent bursae, such as the olecranon bursa located posteriorly over the olecranon to reduce friction during motion.^[4] The medial collateral ligament (MCL), also known as the ulnar collateral ligament, is a primary stabilizer on the medial aspect of the elbow, consisting of three components: the anterior bundle, posterior bundle, and transverse ligament. The anterior bundle originates from the inferior aspect of the medial epicondyle of the humerus and inserts onto the sublime tubercle of the coronoid process of the ulna, forming a fan-shaped structure that is taut in extension and resists valgus stress (medial deviation) during activities like throwing.^[17] The posterior bundle attaches from the medial epicondyle to the medial margin of the olecranon, becoming taut in flexion to further counter valgus forces, while the transverse ligament spans the medial coronoid and olecranon without significant mechanical contribution.^[17] Collectively, the MCL complex maintains medial stability, with its tension varying by elbow position: maximal in the anterior bundle during extension and in the posterior during flexion.^[17] On the lateral side, the lateral collateral ligament (LCL) complex includes the lateral ulnar collateral ligament (LUCL), radial collateral ligament (RCL), and annular ligament, which together prevent varus stress (lateral deviation) and posterolateral rotatory instability. The LUCL arises from the lateral epicondyle of the humerus and fans out to insert into the supinator crest of the ulna, passing deep to the extensor muscles; it is the primary restraint against varus forces and external rotation, with peak tension near full extension.^[17] The RCL connects the lateral epicondyle to the annular ligament, providing additional support, while the annular ligament forms a strong fibrous band encircling the radial head, attaching to the anterior and posterior margins of the radial notch of the ulna to secure the proximal radioulnar joint during pronation and supination. This ligamentous assembly integrates with the capsule, blending fibers to enhance overall joint stability without restricting physiological motion.^[17]

Vascular and Neural Supply

The arterial supply to the elbow region arises primarily from the brachial artery, which courses along the medial aspect of the upper arm and bifurcates into the radial and ulnar arteries at the apex of the cubital fossa, just distal to the elbow joint. This bifurcation provides oxygenated blood to the anterior and medial structures, with the radial artery contributing to the lateral aspect via its recurrent branch and the ulnar artery supplying the medial side through its collateral branches. Additionally, the profunda brachii artery (also known as the deep brachial artery), the largest branch of the brachial artery, travels posteriorly with the radial nerve to supply the posterior compartment, including the triceps brachii, anconeus, and portions of the elbow joint capsule via its middle and radial collateral branches. A key feature of the elbow's vascular architecture is the extensive periarticular anastomotic network, which ensures collateral circulation and includes contributions from the superior ulnar collateral artery (arising proximally from the brachial), inferior ulnar collateral artery (distal brachial branch), anterior and posterior ulnar recurrent arteries, radial recurrent artery, and interosseous recurrent artery; this network encircles the joint and is crucial for maintaining blood flow during movement or potential occlusion.^[18]^[19]^[20]^[17] Venous drainage of the elbow follows both superficial and deep pathways. The superficial system includes the cephalic vein, which drains the lateral forearm and elbow region upward along the lateral arm to join the axillary vein; the basilic vein, draining the medial and posterior aspects medially to the axillary vein; and the median cubital vein, which interconnects the cephalic and basilic veins across the antecubital fossa, often used clinically for venipuncture. Deep veins, known as venae comitantes, parallel the radial, ulnar, and brachial arteries, facilitating drainage from the deeper muscular and joint structures back toward the axillary vein. These systems interconnect via perforating veins, promoting efficient deoxygenated blood return.^[21]^[22] Lymphatic drainage from the elbow region occurs through superficial and deep lymphatic vessels that converge on the axillary lymph nodes, with intermediate drainage via the supratrochlear (infraclavicular) and cubital (epitrochlear) nodes located near the medial elbow. Superficial lymphatics follow the course of the superficial veins, collecting from the skin and subcutaneous tissues, while deep lymphatics accompany the arteries and drain the joint capsule, muscles, and bones; overall, this pathway ensures removal of interstitial fluid and immune surveillance for the upper limb.^[23]^[24]^[25] The neural supply to the elbow encompasses motor innervation to its muscles and sensory supply to the surrounding skin and joint capsule, derived from the brachial plexus via the median (C6-T1 roots), radial (C5-T1), ulnar (C8-T1), and musculocutaneous (C5-C7) nerves. The median nerve, passing anteriorly through the cubital fossa, gives off the anterior interosseous branch proximal to the elbow, which provides motor innervation to the flexor pollicis longus, pronator quadratus, and the lateral half of the flexor digitorum profundus, contributing to forearm pronation and finger flexion. The radial nerve, descending posteriorly before crossing laterally above the elbow, divides into superficial (sensory) and deep branches; the deep branch becomes the posterior interosseous nerve, innervating the extensor muscles such as the supinator, extensor carpi radialis brevis, and extensor digitorum, enabling wrist and finger extension. The ulnar nerve travels posteriorly along the medial epicondyle through the cubital tunnel, providing motor branches to the flexor carpi ulnaris and the medial half of the flexor digitorum profundus for wrist flexion and ulnar deviation. The musculocutaneous nerve pierces the coracobrachialis and supplies the biceps brachii and brachialis muscles, facilitating elbow flexion and supination. Sensory innervation to the joint capsule arises from articular branches of these nerves, ensuring proprioception and pain referral.^[18]^[26]^[27]^[28] Dermatomes and myotomes specific to the elbow reflect its C5-T1 innervation. Dermatomes C6 (lateral forearm), C7 (posterior forearm and middle finger), and C8 (medial forearm and little finger) supply the skin overlying the elbow, with overlap ensuring redundant sensory coverage. Myotomes include C5-C6 for elbow flexion (via biceps and brachialis), C7 for elbow extension (triceps), and contributions from C7-C8 for associated forearm movements like pronation and supination.^[29]^[30]^[31]

Embryological Development

The development of the elbow begins with the formation of the upper limb bud during the fourth week of embryonic gestation, emerging from the ventrolateral body wall mesenchyme derived from the lateral plate somites and somatopleure.^[32] This bud consists of a core of undifferentiated mesenchyme covered by ectoderm, which thickens at the distal margin to form the apical ectodermal ridge (AER), a critical signaling center that interacts with underlying progress zone mesenchyme to direct proximodistal outgrowth and patterning of the limb.^[33] By the fifth week, the limb bud elongates and rotates, establishing the precursors to the humerus, radius, and ulna through mesenchymal condensations along the anteroposterior axis.^[34] Chondrification of these skeletal elements initiates around the sixth to seventh week from the central regions of the mesenchymal condensations, transforming loose mesenchyme into cartilaginous models of the future bones via cellular differentiation into chondrocytes under the influence of signaling molecules such as SOX9 and BMPs.^[35] The elbow joint itself arises from a mesenchymal interzone between the distal humeral and proximal radial/ulnar chondrifying anlagen, which remains avascular and undifferentiated to prevent bony fusion.^[36] Cavitation of this interzone begins by the eighth week (approximately 51 days post-fertilization), where hyaluronan accumulation and cellular apoptosis create minute fluid-filled spaces that coalesce into the synovial cavity, delineating the humeroulnar, humeroradial, and proximal radioulnar articulations.^[36] Ossification follows chondrification, with primary centers appearing in the diaphyses of the humerus, radius, and ulna during the eighth to ninth fetal weeks, but secondary epiphyseal centers appear postnatally, with the capitellum around 1 year of age, the radial head around 5 years, and the olecranon around 10 years.^[37] Disruptions in these processes can lead to congenital anomalies; for instance, radial head dysplasia, the most common elbow malformation, results from failed proximal radial chondrogenesis, often causing posterior dislocation and limited forearm rotation, frequently as part of radial ray deficiency syndromes.^[38] Similarly, syndactyly, arising from AER dysfunction and impaired interdigital apoptosis, may occur alongside radial dysplasia, indirectly affecting elbow alignment through associated forearm bowing or joint instability in complex upper limb malformations.^[39]

Function

Articular Movements

The elbow joint facilitates two primary articular movements: flexion-extension and pronation-supination, enabling a wide range of upper limb functions. Flexion-extension occurs as a hinge motion primarily at the ulnohumeral joint, where the trochlea of the humerus articulates with the trochlear notch of the ulna. This ginglymoid action allows the forearm to move in a sagittal plane relative to the arm, with a normal range from 0° of neutral extension to approximately 145° of flexion.^[40]^[41] Extension is limited by contact between the olecranon process and the olecranon fossa of the humerus, producing a hard, bony end-feel during passive assessment.^[42] In contrast, full flexion is constrained by soft tissue approximation, such as the contact between the biceps brachii muscle belly and the forearm, resulting in a soft end-feel.^[42] Pronation-supination represents a pivot motion at the proximal radioulnar joint, where the circumferential articular surface of the radial head rotates against the radial notch of the ulna, coordinated with similar action at the distal radioulnar joint. This transverse axis rotation permits the forearm to turn approximately 80°-90° into pronation (palm facing downward) and 80°-90° into supination (palm facing upward) from a neutral position.^[43]^[44] The end-feel for both pronation and supination is typically elastic, arising from tension in the ligaments, interosseous membrane, and forearm musculature.^[44] These movements are largely independent, as pronation-supination can occur across the full arc of flexion-extension without direct coupling, though the elbow's carrying angle—a valgus alignment of about 5°-15° in extension—influences the overall kinematic path by orienting the forearm laterally relative to the humerus during rotation.^[45] Active ranges of motion are generally slightly less than passive ones, particularly for flexion, due to interference from antagonist muscle bulk and neural inhibition, whereas passive mobilization can achieve fuller excursion by relaxing these factors.^[42] These motions are primarily driven by key forearm and arm muscles, such as the biceps brachii for both flexion and supination.^[6]

Biomechanics and Carrying Angle

The carrying angle of the elbow refers to the valgus alignment of the forearm relative to the humerus in full extension and supination, typically measuring 11° to 15° in adults.^[18] This angle is measured radiographically by drawing lines along the long axes of the humerus and ulna on anteroposterior views, facilitating assessment of alignment and potential deviations.^[46] The valgus orientation optimizes forearm clearance during arm swing and load carrying, contributing to efficient upper limb function.^[47] Gender and age influence the carrying angle, with females exhibiting a greater mean value (approximately 14°) compared to males (approximately 11°), a difference attributed to secondary sexual characteristics emerging post-puberty.^[18] In females, the angle increases significantly from pre-pubertal to post-pubertal stages due to skeletal remodeling and hormonal effects on bone growth.^[48] This variation diminishes slightly with elbow flexion, as the angle decreases by about 5° to 10° from extension to 90° of flexion.^[49] Biomechanically, the elbow experiences compressive forces primarily along the humero-ulnar and radio-capitellar articulations during flexion, with mean values around 337 N in activities such as push-ups and up to 450 N in cyclic flexion-extension tasks involving light loads (e.g., 2.3 kg).^[50] Torque in pronation-supination averages 8 Nm across daily tasks but can reach 18 Nm for near-body activities and 34 Nm for work-related motions.^[50] These force vectors distribute loads axially and rotationally, with the joint's trochlear-notch geometry directing up to 60% of axial compression to the radiohumeral articulation.^[47] Stability against valgus and varus loading relies on ligamentous tension, particularly the medial collateral ligament (MCL) for valgus resistance and the lateral collateral ligament complex for varus resistance.^[47] At 90° of flexion, the MCL provides approximately 50% of valgus stability, supplemented by joint articulation (25%) and muscle compression forces.^[47] Varus stability is similarly shared, with the radial head and lateral ulnar collateral ligament contributing significantly under loading up to 9 Nm.^[50]

Disorders and Conditions

Traumatic Injuries

Traumatic injuries to the elbow encompass acute disruptions resulting from high-energy impacts, falls, or sudden forces, primarily affecting bones, joints, and surrounding soft tissues. These injuries often occur during falls on an outstretched hand (FOOSH) or direct blows, leading to fractures, dislocations, or soft tissue damage that can compromise elbow stability and function.^[51] Supracondylar humerus fractures are among the most prevalent elbow injuries in children, accounting for up to 60% of pediatric elbow fractures and 18% of all childhood fractures overall. These typically result from a FOOSH mechanism, where axial loading and hyperextension displace the distal humerus. The Gartland classification system categorizes them into types based on displacement: Type I (nondisplaced), Type II (displaced with intact posterior cortex), Type III (completely displaced, often unstable), and Type IV (displaced with rotational instability).^[52]^[53]^[52] Radial head fractures commonly arise from falls onto an outstretched or extended elbow, causing compression or avulsion at the proximal radius. The Mason classification, modified by Hotchkiss, delineates four types: Type I (nondisplaced or minimally displaced <2 mm, no mechanical block), Type II (partial articular with displacement >2 mm or mechanical block), Type III (comminuted), and Type IV (with elbow dislocation). These fractures represent a significant portion of adult elbow trauma, often associated with subtle instability if displaced.^[54]^[55] Olecranon fractures involve the proximal ulna's prominent tip and typically stem from direct trauma, such as a fall onto the elbow or a blow, disrupting the extensor mechanism. These injuries lead to immediate pain, swelling, and inability to actively extend the elbow against resistance, with displacement depending on triceps tension. They account for about 10% of all elbow fractures and are classified by fracture pattern (e.g., transverse, comminuted) and stability.^[56]^[57] Elbow dislocations, the second most common major joint dislocation in adults (after the shoulder) and the most common in children, frequently occur posteriorly due to a FOOSH with hyperextension and axial load, comprising over 90% of cases. This mechanism drives the olecranon posteriorly relative to the humerus, often tearing the medial collateral ligament (MCL) and lateral ulnar collateral ligament (LUCL), with associated injuries like coronoid or radial head fractures in complex cases. Incidence is approximately 6 per 100,000 persons annually, higher in sports-related trauma.^[58]^[59]^[60] Soft tissue traumas include contusions and tendon ruptures, which arise from compressive forces or eccentric loading. Elbow contusions result from direct blunt impacts, causing hemorrhage, swelling, and ecchymosis in the overlying soft tissues without underlying bony disruption, often resolving with conservative measures but risking compartment syndrome if severe. Distal biceps tendon ruptures, typically complete avulsions from the radial tuberosity, occur in middle-aged men during sudden, forceful elbow flexion against resistance (e.g., lifting heavy objects), leading to a characteristic "Popeye" deformity from proximal muscle retraction and acute anterior elbow pain. Nursemaid's elbow, or radial head subluxation, is a common injury in young children (ages 1-4 years), often resulting from axial traction on the pronated forearm such as pulling the arm, accounting for 20% of pediatric upper extremity injuries and occurring more frequently in girls than boys. It presents with sudden pain, refusal to use the arm (pseudoparalysis), and no swelling, and is typically treated with prompt closed reduction.^[51]^[61]^[51]

Inflammatory and Degenerative Diseases

Osteoarthritis of the elbow is a degenerative joint disease characterized by progressive cartilage loss, leading to pain, stiffness, and reduced range of motion. Primary elbow osteoarthritis is uncommon, typically affecting middle-aged men in their dominant arm without prior injury, and is marked by extensive osteophyte formation along the coronoid process and olecranon tip, often resulting in loose bodies within the joint.^[62] These osteophytes contribute to mechanical symptoms like locking or catching, while cartilage erosion is minimal in the ulnohumeral compartment early on, with the radiocapitellar joint frequently spared or showing preserved joint space.^[63] In contrast, secondary osteoarthritis arises from underlying causes such as prior trauma, instability, or crystal deposition, leading to more uniform cartilage thinning across the ulnohumeral and radiocapitellar joints, with osteophytes developing at the radiocapitellar articulation in advanced cases.^[64] Radiographic findings in both forms include marginal osteophytes and subchondral sclerosis, but primary cases emphasize hypertrophic changes over erosive loss.^[65] Rheumatoid arthritis frequently involves the elbow joint through chronic synovial inflammation, affecting 20-65% of patients with the disease, often as part of polyarticular involvement.^[66] The process begins with synovial proliferation and pannus formation, which erode cartilage and subchondral bone, leading to joint space narrowing, marginal erosions, and eventual instability.^[67] In the elbow, this manifests as painless swelling initially, progressing to pain on motion and weakness, with specific deformities including valgus tilt and potential ulnar subluxation due to ligamentous laxity from prolonged synovitis.^[68] Ulnar drift-like deviation may occur secondarily from forearm pronator weakness and radial deviation compensation, exacerbating ulnar nerve compression in advanced stages.^[69] Unlike osteoarthritis, rheumatoid changes are erosive and symmetric, with ultrasound revealing synovial hypertrophy and power Doppler signal indicating active inflammation.^[70] Tendonitis around the elbow, often termed epicondylitis, represents an enthesopathy involving degenerative changes at tendon origins rather than acute inflammation. Lateral epicondylitis, or tennis elbow, affects the extensor carpi radialis brevis (ECRB) origin at the lateral epicondyle, resulting from repetitive wrist extension and gripping, leading to microtears, angiofibroblastic hyperplasia, and collagen disarray.^[71] Symptoms include tenderness over the lateral epicondyle and pain with resisted wrist extension, commonly seen in manual laborers and racket sport participants.^[72] Medial epicondylitis, or golfer's elbow, involves the flexor-pronator group origins at the medial epicondyle, triggered by repetitive forearm pronation and wrist flexion, with similar degenerative pathology including immature vascular ingrowth and tendon thickening.^[73] Both variants cause localized pain radiating to the forearm, reduced grip strength, and occasional ulnar neuropathy in medial cases, with MRI showing increased signal at the enthesis.^[74] Olecranon bursitis involves inflammation of the subcutaneous bursa overlying the olecranon process, often due to repetitive minor trauma or prolonged pressure, such as leaning on the elbow during work or sports.^[75] The superficial location predisposes it to friction-induced irritation, resulting in synovial hyperplasia, fluid accumulation, and bursal wall thickening without significant systemic involvement in aseptic cases.^[76] Clinically, it presents as a fluctuant swelling at the posterior elbow, with minimal pain unless secondarily inflamed, and may limit extension if chronic.^[77] Aspiration typically reveals clear or hemorrhagic fluid, confirming the traumatic etiology over infectious causes.^[78]

Infections and Neurological Complications

Infections of the elbow joint and surrounding structures primarily involve bacterial pathogens that can lead to severe complications if untreated. Septic arthritis, an acute bacterial infection of the synovial joint space, most commonly affects the elbow through hematogenous dissemination from distant sites or direct inoculation via trauma, surgery, or joint procedures.^[79] The predominant causative organism is Staphylococcus aureus, identified in approximately 58.8% of cases in a retrospective review of elbow septic arthritis.^[79] This pathogen often enters via bloodstream seeding in the synovial capillaries, particularly in patients with risk factors such as immunosuppression, diabetes, or prior joint disease.^[79] Osteomyelitis, a bone infection that can involve the distal humerus or proximal ulna adjacent to the elbow, typically arises from similar bacterial sources and pathways as septic arthritis, including hematogenous spread or contiguous extension from soft tissue infections.^[80] Staphylococcus aureus remains the most frequent pathogen across acute and chronic forms, accounting for the majority of cases due to its ability to adhere to bone matrix and form biofilms.^[80] Abscess formation is a common sequela, resulting from inflammatory exudate accumulation that disrupts cortical bone integrity and may require surgical drainage, as antibiotics penetrate poorly into necrotic tissue and pus collections.^[80] In the upper extremity, osteomyelitis affects the humerus in 5-13% of pediatric cases and the ulna in 1-2%.^[81] Neurological complications at the elbow often stem from nerve compression within anatomical tunnels, leading to entrapment neuropathies that impair sensory and motor function. Cubital tunnel syndrome, the most prevalent such condition, involves compression of the ulnar nerve as it passes through the cubital tunnel posterior to the medial epicondyle.^[82] Symptoms include medial elbow pain, paresthesia in the ring and little fingers, and intrinsic hand muscle weakness, with Tinel's sign—elicited by percussion over the nerve—positive in many cases as an indicator of irritation.^[83] Prevalence estimates range from 1.8% to 5.9% in population-based cohorts, making it the second most common upper extremity mononeuropathy after carpal tunnel syndrome.^[82] Other neuropathies affecting the elbow include median and radial nerve entrapments, which are rarer but can mimic or coexist with ulnar involvement. Pronator teres syndrome results from median nerve compression between the heads of the pronator teres muscle near the elbow, often due to repetitive pronation activities or anatomical variants like fibrous bands, presenting with volar forearm pain, proximal median sensory changes, and weakness in thenar muscles.^[84] This condition is uncommon, frequently misdiagnosed as carpal tunnel syndrome, with limited prevalence data but noted associations in up to 18% of carpal tunnel patients showing clinical overlap.^[84] Posterior interosseous nerve syndrome, a form of radial nerve entrapment, occurs distal to the elbow at sites like the arcade of Frohse, causing painless weakness in finger and wrist extension (with radial deviation on dorsiflexion) due to compression of the motor branch, often from trauma or space-occupying lesions.^[85] It is rare, with an annual incidence below 0.7% among upper limb neuropathies.^[86]

Clinical Management

Diagnosis and Assessment

Diagnosis of elbow disorders typically begins with a thorough patient history to identify symptoms such as pain location, onset, aggravating factors, and associated trauma or repetitive activities, followed by a comprehensive physical examination.^[87] The physical examination includes assessment of range of motion through active and passive flexion, extension, supination, and pronation, with normal elbow flexion ranging from 0° to 145° and extension to 0°.^[88] Valgus and varus stress tests are performed at 20°-30° of flexion to evaluate medial and lateral collateral ligament stability, respectively, where increased laxity or pain may indicate instability.^[88] Palpation focuses on key structures including the medial and lateral epicondyles, olecranon, and radial head to detect tenderness, swelling, or crepitus suggestive of inflammation or injury.^[87] Provocative tests aid in identifying specific conditions; Cozen's test, involving resisted wrist extension with the elbow extended and forearm pronated, reproduces pain at the lateral epicondyle in cases of lateral epicondylitis (tennis elbow).^[89] Tinel's sign, elicited by tapping over the ulnar nerve at the cubital tunnel, produces paresthesia in the ring and little fingers if positive, indicating ulnar neuropathy.^[77] Imaging modalities are selected based on suspected pathology; plain radiographs in anteroposterior (AP) and lateral views are initial studies for detecting fractures, dislocations, or bony abnormalities.^[90] Magnetic resonance imaging (MRI) provides detailed evaluation of soft tissues, including ligaments, tendons, and cartilage, particularly for internal derangement or occult injuries.^[90] Ultrasound is useful for dynamic assessment of tendons and effusions, offering real-time visualization of structures like the common extensor tendon in tendinopathy.^[77] Laboratory investigations support diagnosis in cases of suspected inflammation or infection; erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are elevated in inflammatory conditions such as rheumatoid arthritis affecting the elbow.^[91] For infectious processes like septic arthritis, blood and synovial fluid cultures are essential to identify pathogens, alongside elevated white blood cell count, ESR, and CRP.^[92]

Treatment Approaches

Treatment approaches for elbow conditions encompass a range of conservative, pharmacologic, and surgical strategies, tailored to the specific injury or disorder, with rehabilitation playing a central role in recovery. Conservative management is often the first-line approach for acute and chronic elbow issues, emphasizing non-invasive methods to reduce pain, inflammation, and promote healing. The RICE protocol—rest, ice, compression, and elevation—is widely recommended immediately following injury to minimize swelling and protect the joint. Bracing, such as counterforce straps, is particularly effective for conditions like lateral epicondylitis (tennis elbow), where it offloads stress from the extensor tendons by applying localized pressure. Recent evidence (as of 2024) supports adjunctive use of regenerative therapies, such as platelet-rich plasma (PRP) injections, for refractory tendinopathies like lateral epicondylitis, though long-term efficacy varies.^[93] Physical therapy focuses on restoring range of motion (ROM) through targeted exercises, including stretching and strengthening of forearm muscles, typically progressing from passive to active movements over several weeks. Pharmacologic interventions complement conservative measures by addressing pain and inflammation. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are commonly prescribed to reduce swelling and discomfort in various elbow pathologies, including tendinopathies and minor sprains. For more localized inflammation, such as in olecranon bursitis, corticosteroid injections provide rapid relief by suppressing the immune response in the affected bursa, though they are used judiciously to avoid tendon weakening. Surgical options are reserved for cases where conservative treatments fail or for severe structural damage, aiming to restore anatomy and function. Open reduction and internal fixation (ORIF) is the standard procedure for displaced elbow fractures, involving realignment of bone fragments and stabilization with plates or screws to ensure proper healing and prevent malunion. Ligament reconstruction, often using autografts, addresses instability from ruptures like those in the ulnar collateral ligament, commonly seen in athletes.^[94] Recent advances include internal brace augmentation for ulnar collateral ligament repair, particularly in throwing athletes, to enhance stability and accelerate return to sport (as of 2019–2025).^[95] Ulnar nerve transposition surgically relocates the nerve to alleviate compression in cubital tunnel syndrome, reducing symptoms like numbness and weakness. Rehabilitation follows a phased progression to optimize outcomes across all treatment modalities. The acute protection phase involves immobilization and pain control to allow initial healing, typically lasting 1-2 weeks. This transitions to an intermediate phase emphasizing controlled ROM exercises and gradual strengthening, followed by a functional restoration phase that incorporates sport- or work-specific activities to regain full elbow stability and endurance, often spanning 3-6 months depending on the condition.

Comparative Anatomy

In Other Primates

In non-human primates, the elbow joint exhibits variations adapted to diverse locomotor styles, contrasting with human bipedalism. Quadrupedal apes, such as chimpanzees and gorillas, possess a narrower carrying angle at the elbow, typically ranging from 0° to 5°, which aligns the forearm closely with the humerus to facilitate stable weight-bearing during terrestrial locomotion like knuckle-walking.^[96] In contrast, arboreal species like gibbons demonstrate greater elbow flexion capacity to support suspensory behaviors such as brachiation, where the joint must accommodate dynamic overhead swinging and rapid repositioning of the forelimbs.^[97] Ligamentous structures in the primate elbow also reflect locomotor demands, with brachiating species showing reinforced lateral collateral ligaments for enhanced overhead stability. In gibbons and other hylobatids, these ligaments are particularly robust, providing resistance to varus stresses during suspension and preventing subluxation when the body weight is suspended from extended arms.^[98] This adaptation contrasts with the relatively less emphasized lateral support in quadrupedal Old World monkeys, where medial ligaments play a larger role in pronated postures. Muscle architecture varies across primate taxa to optimize forearm function. In Old World monkeys like macaques, the pronator teres is enhanced with a prominent humeral head originating from the medial epicondyle, enabling powerful pronation essential for grasping and quadrupedal progression on varied substrates.^[99] Such modifications support precise control during terrestrial and arboreal activities, differing from the more balanced pronator-supinator configuration in humans geared toward manipulative tasks. Specific examples illustrate these adaptations' functional roles. The chimpanzee elbow, with its short olecranon process and powerful triceps brachii (physiological cross-sectional area of approximately 35.4 cm²), is specialized for knuckle-walking, allowing rapid extension and hyperextension to absorb impacts and maintain stability during quadrupedal gait.^[100] These features highlight a divergence from human elbow morphology, which evolved toward greater precision grip capabilities for tool use and bipedal carrying, underscoring locomotor shifts in hominid evolution.^[101]

Evolutionary Perspectives

The evolutionary development of the elbow in hominins reflects adaptations to bipedalism and enhanced manual dexterity, as seen in fossil records spanning millions of years. In Australopithecus species, such as A. afarensis from approximately 3.2 million years ago, elbow joint morphology shows transitional features, including minimal or no significant carrying angle, which supported a mix of arboreal climbing and emerging terrestrial locomotion without the full valgus alignment of later hominins.^[102]^[103] This configuration allowed for efficient weight-bearing during knuckle-walking or occasional upright posture but limited the degree to which the forearm could swing clear of the body during bipedal gait. By contrast, Homo erectus fossils, dating to about 1.8 million years ago, exhibit elbow structures with a more pronounced carrying angle similar to modern humans, facilitating better alignment of the upper limb with the body's center of mass and reducing interference with the hips during walking.^[104]^[105] A key adaptation in the Homo lineage, emerging around 2.5 million years ago with the advent of systematic tool use, involved an expanded range of forearm supination. This enhancement, exceeding that of earlier australopiths, enabled greater rotational freedom at the elbow—up to 90° or more of supination—critical for precise gripping and manipulative tasks such as flaking stone tools or wielding implements.^[106]^[107] Such changes likely arose from modifications in the radial head and ulnar trochlear notch, allowing Homo species to perform complex actions that demanded sustained pronation-supination cycles beyond the primarily suspensory demands of primate ancestors.^[108] Genetic mechanisms underlying these evolutionary shifts center on HOX gene clusters, which orchestrate limb patterning along the proximal-distal axis, including the elbow region's joint formation and muscle attachments. HoxD genes, in particular, regulate the timing and spatial expression of skeletal elements during embryogenesis, with variations in their regulatory sequences contributing to the elongation and specialization of forelimb structures in hominins over evolutionary time.^[109]^[110] These genes' conserved role across vertebrates underscores how subtle regulatory evolution could refine elbow functionality for bipedal stability and tool-related precision without major morphological overhauls.^[111] Insights from pathology highlight potential evolutionary mismatches in the modern elbow, where overuse injuries like medial epicondylitis arise from repetitive motions that exceed the joint's ancestral design tolerances. Evolved primarily for intermittent high-velocity actions such as throwing projectiles—optimized around 2 million years ago with Homo erectus—the elbow lacks robust adaptations for the prolonged, low-intensity repetitions common in contemporary activities like typing or sports training, leading to heightened vulnerability in tendon and ligament structures.^[112]^[113] This mismatch illustrates how rapid cultural and technological changes have outpaced musculoskeletal evolution, amplifying injury risks in non-locomotor contexts.

References

[1]
Elbow Joint: Anatomy, Function & Common Conditions
Feb 7, 2024 · The elbow joint is where your humerus (your upper arm bone) meets your radius and ulna (the two bones in your forearm). It joins your upper arm ...
[2]
Elbow joint: Anatomy, ligaments, movements, blood supply | Kenhub
It is the point of articulation of three bones: the humerus of the arm and the radius and the ulna of the forearm. The elbow joint is classified structurally ...
[3]
The Elbow Joint - Structure - Movement - TeachMeAnatomy
The elbow is the joint connecting the upper arm to the forearm. It is classed as a hinge-type synovial joint.
[4]
Anatomy, Shoulder and Upper Limb, Biceps Muscle - NCBI - NIH
Jan 30, 2024 · The biceps brachii is primarily a strong forearm supinator but a weak elbow flexor.[8] The brachialis is the primary forearm flexor.
[5]
Anatomy, Shoulder and Upper Limb, Brachialis Muscle - NCBI - NIH
The brachialis is an elbow flexor that originates from the distal anterior humerus and inserts onto the ulnar tuberosity.
[6]
Anatomy, Shoulder and Upper Limb, Forearm Brachioradialis Muscle
Jan 30, 2024 · The brachioradialis primarily acts as an elbow flexor. The muscle is active during elbow flexion, whether the forearm is supinated, neutral, or pronated.Blood Supply And Lymphatics · Surgical Considerations · Clinical Significance
[7]
Anatomy, Shoulder and Upper Limb, Wrist Extensor Muscles
Aug 28, 2023 · Anconeus origin: lateral epicondyle of the humerus; Anconeus insertion: olecranon and proximal posterior ulna. The deep compartment originates ...
[8]
Anatomy, Shoulder and Upper Limb, Pronator Teres - NCBI - NIH
May 1, 2023 · The pronator teres is a fusiform forearm muscle found in the superficial layer of the anterior compartment of the forearm.
[9]
Anatomy, Shoulder and Upper Limb, Forearm Muscles - StatPearls
Two muscular compartments - an anterior (flexor) and posterior (extensor) compartment - contain together twenty muscles that act on the elbow and wrist joints, ...
[10]
Anatomy, Shoulder and Upper Limb, Muscles - StatPearls - NCBI - NIH
The upper limb comprises many muscles which are organized into anatomical compartments. These muscles act on the various joints of the hand, arm, and shoulder.
[11]
A 3-Dimensional Anatomic Study of the Distal Biceps Tendon
Jun 2, 2015 · Total length of the tendon (both internal and external) was 126.7 ± 10.7 mm. Average internal tendon length was 63.8 ± 11.6 mm, while the ...
[12]
Anatomy, Shoulder and Upper Limb, Forearm Extensor Carpi ... - NCBI
The extensor carpi radialis brevis originates from the lateral epicondyle of the humerus by a common tendon shared with other muscles of the posterior ...
[13]
Anatomy, Shoulder and Upper Limb, Elbow Joint - StatPearls - NCBI
Jul 24, 2023 · The elbow is a synovial hinge joint made up of articulations of mainly the distal humerus and the proximal ulna.Missing: origins | Show results with:origins
[14]
Anatomy, Shoulder and Upper Limb, Elbow Collateral Ligaments
The elbow contains two collateral ligaments: the medial collateral ligament (MCL, also known as ulnar collateral ligament, or UCL) and the lateral collateral ...
[15]
Elbow Anatomy & Biomechanics - Shoulder & Elbow - Orthobullets
Mar 24, 2024 · Musculocutaneous nerve · lateral cord of the brachial plexus · it will terminate as the LABC (forearm), which is found deep to the cephalic vein.
[16]
Anatomy, Shoulder and Upper Limb, Brachial Artery - NCBI - NIH
Profunda Brachii/ Deep Brachial Artery ... Superior ulnar collateral artery: supplies the periarticular arterial anastomoses of the elbow and elbow joint.Introduction · Structure and Function · Muscles · Physiologic Variants
[17]
Anatomy, Shoulder and Upper Limb, Profunda Brachii Artery - NCBI
Nov 5, 2023 · The profunda brachii artery provides additional circulation to the deltoid, triceps brachii, and anconeus. Go to: Physiologic Variants.
[18]
https://www.orthobullets.com/shoulder-and-elbow/3078/elbow-anatomy-and-biomechanics
[19]
Venous drainage of the upper extremities - NCBI - NIH
The venous drainage of the upper extremities is again divided into a superficial and deep system. The dorsal digital veins are highly interconnected.
[20]
Lymphatic drainage of the upper limb | Radiology Reference Article
Jan 22, 2022 · Lymphatic drainage of the upper limb is via a series of deep and superficial channels that ultimately drain into the axillary lymph nodes.
[21]
Lymphatic Drainage of the Upper Limb - Vessels - TeachMeAnatomy
This article will explore the anatomy of lymphatic drainage throughout the upper limb – the lymphatic vessels, lymph nodes, and its clinical correlations.
[22]
Epitrochlear lymph nodes: Anatomy, clinical aspects, and ...
As a general rule, the epitrochlear station drains the lymph from the last two or three fingers and from the medial aspect of the hand itself.Anatomic Aspects · Fig. 2 · Fig. 4<|separator|>
[23]
Anatomy, Shoulder and Upper Limb, Forearm Anterior Interosseous ...
The anterior interosseous nerve (AIN) is predominantly a motor neuron. It is a branch of the median nerve, which is formed from the roots of the fifth, sixth, ...
[24]
Anatomy, Shoulder and Upper Limb, Radial Nerve - StatPearls - NCBI
Nov 5, 2023 · Meanwhile, the deep branch of the radial nerve pierces the supinator, travels around the lateral margin of the radius' neck, and enters the ...Missing: insertion | Show results with:insertion
[25]
Cubital Tunnel Syndrome - StatPearls - NCBI Bookshelf - NIH
Aug 14, 2023 · Cubital tunnel syndrome is neuropathy of the ulnar nerve causing symptoms of numbness and shooting pain along the medial aspect of the forearm.Cubital Tunnel Syndrome · Introduction · Treatment / Management<|separator|>
[26]
Dermatomes and Myotomes | Sensation | Anatomy Geeky Medics
May 14, 2018 · C6: wrist extension; C7: elbow extension and wrist flexion; C8: thumb extension and finger flexion; T1: finger abduction; L2: hip flexion; L3 ...
[27]
Myotomes - Development - Distribution - TeachMeAnatomy
Distribution of Myotomes ; Upper Limb, Lower Limb ; C5 – Shoulder abduction; C6 – Elbow flexion; C7 – Elbow extension; C8 – Finger flexion; T1 – Finger abduction.
[28]
Myotomes - Physiopedia
C6- Elbow flexion & wrist extension. Test the strength of forearm flexion by ... C7- Elbow extension & wrist flexion. Instruct the patient to extend ...Muscle Strength Testing · Edit · Contents Editors
[29]
Formation of the Limb Bud - Developmental Biology - NCBI Bookshelf
As mesenchyme cells enter the limb region, they secrete factors that induce the overlying ectoderm to form a structure called the apical ectodermal ridge (AER) ...Specification of the limb fields... · Induction of the early limb bud...
[30]
Embryology - Basic Science - Orthobullets
Jul 22, 2022 · enlargement of the limb bud is due to the interaction between the apical ectodermal ridge (AER) and the mesodermal cells in the progress zone.
[31]
https://www.physio-pedia.com/Myotomes
[32]
Embryology and Developmental Anatomy of the Elbow | Clinical Gate
Apr 17, 2015 · The elbow joint develops from mesenchymal interzones. The mesenchymal interzone between the chondrifying bone ends differentiates into ...
[33]
None
Nothing is retrieved...<|separator|>
[34]
https://teachmeanatomy.info/the-basics/embryology/development-limbs/
[35]
Congenital Radial Head Dislocation - Hand - Orthobullets
Sep 23, 2025 · appears too long compared to the ulna. Associated conditions. may have concurrent congenital anomalies. Anatomy. Elbow Anatomy & Biomechanics.
[36]
Embryology, diagnosis, and evaluation of congenital hand anomalies
Defects in the AER lead to anomalies such as limb truncation, transverse deficiencies, and syndactyly [9]. ... abnormalities of the elbow and forearm. The ...Thumb Hypoplasia · Syndactyly · Polydactyly<|control11|><|separator|>
[37]
Normal Range of Motion Reference Values - Eaton Hand
Typical Range of Motion. Elbow, Extension/Flexion, 0/145. Forearm, Pronation/Supination, 70/85. Wrist, Extension/Flexion, 70/75. Radial\Ulnar, 20/35.
[38]
Elbow anatomy, biomechanics and clinical examination
The normal range of motion is from 0° (full extension) to 145° (full flexion). Most functional activities only require a range of motion from 30° to 130°.Missing: ulnohumeral | Show results with:ulnohumeral
[39]
MEASUREMENT of RANGE of MOTION of the ELBOW and FOREARM
Aug 10, 2016 · The range of elbow flexion tends to be greater when the joint is moved passively because there is less interference by contracting muscle bulk.Elbow Joint · Forearm Joints · Range Of Motion And...Missing: ulnohumeral | Show results with:ulnohumeral
[40]
Learn about the Normal Joint Range of Motion Study - CDC Archive
Reference Values for Normal Joint Range of Motion ; Elbow extension · Elbow pronation · Elbow supination ; 6.8 (5.2 – 8.4) · 84.6 (82.8 – 86.4) · 93.7 (91.4 – 96.0).
[41]
Normative values and affecting factors for the elbow range of motion
According to the literature, values for flexion lie between 130° and 154° and extension between –6° and 11°. Pronation varied from 75° to 85° and supination ...
[42]
Biomechanics of the Elbow - Musculoskeletal Key
Aug 28, 2016 · If the first or second definition is accepted, the carrying angle changes minimally during flexion. The specific varus/valgus relationship of ...
[43]
Elbow Radiographic Anatomy: Measurement Techniques and ...
While we did confirm a statistically distinct difference between males and females; the 2-degree higher carrying angle in females is a minimal clinical ...
[44]
The Anatomy and Biomechanics of the Elbow
Aug 19, 2020 · The elbow joint is a trochoginglymoid joint: that is, it has flexion-extension [ginglymoid] motion at the ulnohumeral and radiocapitellar ...INTRODUCTION · ELBOW ANATOMY · MEDIAL COLLATERAL...
[45]
Near absent carrying angles: a clinical clue to underlying SHOX ...
Mar 31, 2019 · This sexual dimorphism though not universal in prepubertal children, usually increases in girls post puberty; hence, carrying angle may be ...
[46]
The Effect of Elbow Flexion On Valgus Carrying Angle - PubMed
All elbows decreased their valgus carrying angle during flexion from 0° to 90° when the arm was maintained at 0° of humerothoracic abduction.
[47]
Elbow joint biomechanics during ADL focusing on total elbow ... - NIH
Jan 18, 2023 · Aim is therefore to evaluate the elbow joint load during activities of daily living (ADL) and compare these loads with reported failure limits.Missing: reaction | Show results with:reaction
[48]
Elbow Trauma - StatPearls - NCBI Bookshelf
Apr 19, 2024 · Accounts for 20% of all upper extremity injuries in children · Peak age 1 to 4 · Occurs more frequently in girls than boys · Mechanism of injury: ...Elbow Trauma · History And Physical · Treatment / Management<|separator|>
[49]
Supracondylar Humerus Fractures - StatPearls - NCBI Bookshelf - NIH
Supracondylar fractures of the humerus account for up to 18% of pediatric fractures and 60% of elbow fractures.
[50]
The Gartland Classification of Supracondylar Humerus Fractures - NIH
Gartland described a simple classification scheme to reemphasize principles underlying treatment of patients with a supracondylar humerus fracture.Missing: mechanism | Show results with:mechanism
[51]
Radial Head Fractures - Trauma - Orthobullets
Sep 29, 2025 · Mason Classification. (Modified by Hotchkiss and Broberg-Morrey) ; Type I. Nondisplaced or minimally displaced (<2mm), no mechanical block to ...
[52]
Mason classification of radial head fractures - Radiopaedia.org
Aug 13, 2024 · The Mason classification ( sometimes known as Mason-Johnston classification) is used to classify radial head fractures and is useful when assessing further ...
[53]
Elbow (Olecranon) Fractures - OrthoInfo - AAOS
Anatomy. The elbow is a joint made up of three bones: The humerus (upper arm bone) The radius (forearm bone on the thumb side)
[54]
Olecranon Fractures - Trauma - Orthobullets
Feb 14, 2024 · Olecranon Fractures are common fractures of the elbow that lead to loss of extensor mechanism. Diagnosis can be made with plain radiographs of ...
[55]
Elbow Dislocation: Practice Essentials, Epidemiology, Functional ...
Nov 16, 2022 · More than 90% of elbow dislocations are posterior dislocations. Dizdarevic et al reported 9.2% of all elbow injuries in high school athletics ...Practice Essentials · Epidemiology · Functional Anatomy
[56]
Posterior Elbow Dislocation - StatPearls - NCBI Bookshelf
During a posterior elbow dislocation, the shearing forces causing the injury may cause associated radial head, radial neck or coronoid process fractures. The ...Continuing Education Activity · Introduction · Pathophysiology · History and Physical
[57]
Elbow Dislocations: A Review Ranging from Soft Tissue Injuries to ...
In elbow dislocations, single ligamentous or capsular injuries are rare [31]. Patients with stages 1 and 2 of elbow dislocations may be treated by distraction ...
[58]
Biceps Tendon Tear at the Elbow - OrthoInfo - AAOS
In most cases, tears of the distal biceps tendon are complete. This means that the entire muscle is detached from the bone and pulled toward the shoulder.
[59]
Primary Elbow Osteoarthritis: Evaluation and Management - PMC
May 9, 2021 · Unlike hip and knee OA, primary elbow OA is characterized by the widespread formation of osteophytes and loose bodies, capsular contracture, and ...Missing: secondary | Show results with:secondary
[60]
[PDF] Current concepts review: Management of elbow osteoarthritis
Feb 1, 2006 · The radiographs show osteophytes but well-preserved ulnohumeral and radiocapitellar joint spaces, which are charac- teristic of primary ...
[61]
An Overview of the Pathogenesis and Treatment of Elbow ... - NIH
May 29, 2019 · Primary osteoarthritis is radiographically detected by noticing characteristic osteophytes on the coronoid process and olecranon. The absence of ...2.1. Primary Elbow... · 3.3. Imaging · 4.2. Surgical Treatment
[62]
Radiographic changes at the elbow in primary osteoarthritis
In the osteoarthritic group, osteophytes of the olecranon (96%), coronoid process (90%), radial head (86%), and coronoid and radial fossae (64%) were the most ...Missing: involvement | Show results with:involvement
[63]
Inflammatory arthritis and the elbow surgeon - PMC - NIH
1.1. The most common inflammatory arthropathy is rheumatoid arthritis (RA) with the elbow involved as a monoarthropathy in 5% and as part of a polyarthropathy ...
[64]
Incidence of elbow involvement in rheumatoid arthritis. A 15 year ...
Conclusion: After 15 years more than half of the elbows and almost 2 of 3 patients with RA showed definite involvement of the elbow joint. Erosions were most ...Missing: prevalence | Show results with:prevalence
[65]
Prevalence of Elbow Joint Arthritis and Enthesitis in Rheumatoid ...
May 24, 2020 · The prevalence of elbow arthritis in RA seems to be high, with 35.29%. Movement restriction is a good indicator, but not in all RA patients.
[66]
Hand and Wrist Rheumatoid Arthritis - StatPearls - NCBI Bookshelf
Ulnar drift or ulnar deviation: this deformity develops as a complication to weakening with laxity or erosion of the extensor carpi ulnaris tendon overlying ...
[67]
Prevalence of Elbow Joint Arthritis and Enthesitis in Rheumatoid ...
Abstract. Objectives: The prevalence of elbow joint arthritis in rheumatoid arthritis (RA) assessed by ultrasound has not yet been investigated.
[68]
Lateral Epicondylitis (Tennis Elbow) - StatPearls - NCBI Bookshelf
Lateral epicondylitis, also commonly referred to as tennis elbow, describes an overuse injury secondary to an eccentric overload of the common extensor ...Missing: flexor | Show results with:flexor
[69]
Lateral epicondylitis of the elbow - PMC - NIH
Nov 22, 2016 · Lateral epicondylitis was first described by Runge in 1873. It was described as a chronic symptomatic degeneration of the wrist extensor tendons ...Diferential Diagnosis · Treatment · Imaging Studies<|separator|>
[70]
Medial Epicondylitis - StatPearls - NCBI Bookshelf - NIH
May 2, 2024 · This condition typically arises due to repetitive stress from activities involving forearm pronation or wrist flexion.Missing: enthesopathy | Show results with:enthesopathy
[71]
Common tendinopathies around the elbow; what does current ... - NIH
May 21, 2021 · Lateral epicondylitis usually arises from any activity that requires overuse of the proximal origins of the wrist common extensors, resulting in ...Missing: enthesopathy | Show results with:enthesopathy
[72]
Olecranon Bursitis - StatPearls - NCBI Bookshelf - NIH
Olecranon bursitis refers to inflammation of the bursa. The superficial location and limited vascularity make the bursa susceptible to trauma and infection.
[73]
Olecranon bursitis: a systematic overview - PMC - NIH
Most commonly, olecranon bursitis is a non-infective, post-traumatic, inflammatory response to repetitive, minor trauma. Historically, this has prompted the ...
[74]
[PDF] ELBOW DISORDERS - California Department of Industrial Relations
Causal mechanisms are somewhat unclear, but thought to include direct trauma over the olecranon such as bumping or falling on the elbow or leaning on the ...
[75]
Chronic Bilateral Olecranon Bursitis: A Case Report - PMC - NIH
Jul 31, 2024 · Chronic bilateral olecranon bursitis is a rare but debilitating condition, especially for individuals engaged in repetitive manual labor, such as truck drivers.Missing: causes | Show results with:causes
[76]
Septic Arthritis of the Elbow: A 10-Year Retrospective Clinical and ...
Mar 23, 2025 · Infection can enter the joint through different routes: (a) hematogenous dissemination leading to pathogen lodging in synovial capillaries; (b) ...Missing: spread | Show results with:spread
[77]
Osteomyelitis - StatPearls - NCBI Bookshelf - NIH
May 31, 2023 · Osteomyelitis is a serious infection of the bone that can be either acute or chronic. It is an inflammatory process involving the bone and its structures.Missing: ulna | Show results with:ulna
[78]
Osteomyelitis and Septic Arthritis of the Upper Extremity in Pediatric ...
Dec 24, 2024 · Seeding of the bone and joint frequently occurs due to hematogenous spread but can also be the result of direct inoculation or contiguous spread ...
[79]
The Prevalence of Cubital Tunnel Syndrome: A Cross-Sectional ...
Mar 1, 2017 · Based on this cross-sectional survey of a healthy, population-based cohort, we found that between 1.8% and 5.9% of individuals reported symptoms ...
[80]
A Clinical Scoring System for Distinguishing Patients With ... - NIH
Results: Decreased intrinsic muscle strength, decreased ulnar sensation, positive elbow flexion test, positive cubital tunnel Tinel's sign, and abnormal NCS ...
[81]
Pronator Teres Syndrome - StatPearls - NCBI Bookshelf - NIH
Jul 3, 2023 · Pronator teres syndrome (PTS) is caused by compression of the median nerve by the pronator teres muscle in the forearm.Missing: origin insertion
[82]
Posterior Interosseous Nerve Syndrome - StatPearls - NCBI Bookshelf
Compression neuropathies of the radial nerve distal to the elbow include radial tunnel syndrome, posterior interosseous nerve syndrome, and Wartenberg syndrome.Continuing Education Activity · Introduction · Differential Diagnosis
[83]
Posterior Interosseous Neuropathy: Electrodiagnostic Evaluation - NIH
Posterior interosseous neuropathy is an entrapment of the deep branch of the radial nerve in the forearm. The deep branch of the radial nerve is primarily a ...Case Report · Fig. 1 · Discussion
[84]
Elbow pain: a guide to assessment and management in primary care
Flexion, supination, and pronation should all be tested. Wrist movements should also be assessed because of the shared musculature between wrist and elbow.
[85]
Elbow Physical Exam - Shoulder & Elbow - Orthobullets
Feb 29, 2024 · Steps to physical exam, inspection, swelling patients with elbow effusion will generally hold elbow flexed at 70-80 degrees flexion at rest.
[86]
Differential Diagnosis of Elbow Pain - PMC - NIH
Cozen's test, a standard physical examination, is conducted by passively flexing the wrist joint while the elbow joint is extended, or when the examiner ...
[87]
[PDF] Elbow Injuries - Workers' Compensation Board
May 2, 2022 · Most patients with olecranon bursitis are treated with soft elbow padding, support ... D.3.f.ii Surgical Resection for Chronic Olecranon Bursitis.
[88]
Monarticular rheumatoid arthritis of the elbow - PMC - PubMed Central
Mar 7, 2022 · The worldwide prevalence of RA is about 0.5%–1% and occurs more frequently in middle-aged women.
[89]
Chapter XIX.5. Septic Arthritis - Case Based Pediatrics Chapter
The most important lab studies for septic arthritis are blood cultures, CBC, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) (1). These ...
[90]
Why Do Knuckle-Walking African Apes Knuckle-Walk?
View of an African ape's hand and wrist bones in lateral view during knuckle ... Brachiation in New World monkeys and in anthropoid apes. Symp Zool S ...<|separator|>
[91]
Functional anatomy of the gibbon forelimb: adaptations to a ... - NIH
Also important to note is that we found no anconeus lateralis muscle in any of our gibbon specimens, leaving the triceps as the only elbow extensor in gibbons.
[92]
Another look at the anthropoid elbow - ScienceDirect.com
Major differences in the humeroulnar joint relate mostly to different means of stabilizing the joint. In extant hominoids, Oreopithecus, and ramapithecines the ...
[93]
The forearm and hand musculature of semi‐terrestrial rhesus ...
Jun 8, 2020 · Primates live in very diverse environments and, as a consequence, show an equally diverse locomotor behaviour. During locomotion, the primate ...
[94]
Elbow Extensor Muscles in Humans and Chimpanzees: Adaptations ...
Oct 30, 2022 · We have found that the triceps brachii of chimpanzees is more prepared for strength and power as an adaptation to locomotion.
[95]
Independent evolution of knuckle-walking in African apes shows that ...
Aug 25, 2009 · The presence of such morphology across all African apes would provide strong evidence that these features are indeed knuckle-walking adaptations ...
[96]
Limb Bone Structural Proportions and Locomotor Behavior in A.L. ...
Nov 30, 2016 · Here we examine bone structural properties of the femur and humerus in the Australopithecus afarensis AL 288–1 ("Lucy", 3.2 Myr) that are known to be ...
[97]
An early Australopithecus afarensis postcranium from Woranso-Mille ...
Articulation with KSD-VP-1/1b shows no significant “carrying angle.” The ulnar tuberosity is well preserved and is most similar to those of humans. Shaft ...
[98]
Homoplasy in the evolution of modern human-like joint proportions ...
May 12, 2021 · Here, we find the limb joint proportions of Australopithecus afarensis, Homo erectus, and Homo naledi to resemble those of modern humans.Missing: carrying angle
[99]
Locomotion and posture from the common hominoid ancestor to fully ...
... brachiating' arboreal orthograde gibbon-like primates, the 'hylobatians'. ... monkeys, where the lumbar spine is laterally flexible. In living hominoids ...
[100]
Analysis of the forearm rotational efficiency in extant hominoids
Chimpanzees and gorillas use knuckle-walking, a unique form of quadrupedalism, although they engage in it to different degrees: whereas eastern gorillas are ...
[101]
Tool making, hand morphology and fossil hominins - PubMed Central
... range of behaviours, even beyond those involving tools. ... EMG of the human flexor pollicis longus muscle: implications for the evolution of hominid tool use.Missing: supination | Show results with:supination
[102]
Articular morphology of the proximal ulna in extant and fossil ...
This paper explores the three- and two-dimensional morphology of the trochlear notch of the elbow of extant hominoids and fossil hominins and hominoids.
[103]
Hox Genes: The Evolution of Limbs from Fins - iBiology
Neil Shubin used a combination of fossil record and modern genetics to study the role of Hox genes in the evolution of limb development.Speaker Bio · Neil Shubin · More Talks In Evolution
[104]
Why we have (only) five fingers per hand: Hox genes and the ...
Oct 1, 1992 · The expression patterns of Hox genes in modern embryonic limb buds also gives clues to the shape of the ancestral fin field from which the limb ...
[105]
The role of timing in the development and evolution of the limb - PMC
May 2, 2023 · We illustrate how timing mechanisms have been used to establish the correct pattern of the limb and provide cases where natural variations in timing have led ...Limb Outgrowth And Its... · Heterochrony And Digit... · Heterochrony In The Timing...
[106]
A Segmental Approach to Imaging of Sports-Related Injuries of ... - NIH
The greater load of repetitive motion leads to an increased incidence of overuse injuries about the elbow. As the ossification centers about the elbow develop ...
[107]
Overuse injuries in sport: a comprehensive overview
Dec 5, 2018 · The purpose of this compressive review is to give an overview of overuse injuries in sport by describing the theoretical foundations of these conditions.Missing: mismatch | Show results with:mismatch